INTRODUCTION
• The abdominal x-ray has become a less frequently
requested x-ray.
• However, there is a great deal of information which can
be found on an abdomen x-ray.
• Routine projections are the supine and erect projections
• Additional views are decubitus views and the lateral
abdomen
OBJECTIVES
• Normal abdomen appearances
• Abnormal appearances
• Additional projections
• Abdominal X-rays are only useful for certain defined
pathology such as abnormal ‘gases, masses, bones and
stones’.
TECHNICAL FACTORS
OPTIMUM EXPOSURE
Key to densities in AXRs
● Black—gas
● White—calcified structures
● Grey—soft tissues
● Darker grey—fat
● Intense white—metallic objects
NORMAL ABDOMEN
• Check medical legal
prerequisites
• Date of the image
• Projection supine or
erect
ERECT
SUPINE
INTRALUMINAL GAS
• Evaluate the position of
the large and small
bowel pattern
remembering there is a
great deal of normal
variation in the
distribution.
• Large bowel – 5cm
• Small bowel – 3cm
MUCOSAL PATTERNS
• Small bowel patterns
• Centrally positioned
• Valvulae conniventes (stack
of coins) are visualised
across the entire width of
the intestine
MUCOSAL PATTERNS
• Large bowel
• Picture frame
• Haustral pattern cross
only part of the width of
the intestine
FAECAL LOADING
• Faeces gives a mottled
appearance
• Due to the combination of
liquid and solid elements
EXTRALUMINAL GAS
EXTRALUMINAL GAS
• Nearly always abnormal
• Often seen in large quantities under the right diaphragm
• Gas in the peritoneal cavity is called a
pneumoperitoneum
• Gas maybe seen in the biliary tree maybe normal post
surgery or indicate a fistula between the biliary tree and
the bowel
• Gas in the portal vein may occur associated with toxic
megacolon
CALCIFICATION
• An 87-year-old woman was
admitted to our hospital with
a clinical history including
fever, foetid grey vaginal
discharge and a confused
state that had developed
over the previous week.
• Provide pattern recognition
for this image and suggest
other modalities for the
assessment of the
abnormality
CALCIFICATION
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Normal structures that
calcify
● Costal cartilage
● Mesenteric lymph nodes
● Pelvic vein clots
(phlebolith)
CALCIFICATIONS
• Increase with age
• Check:
• Liver – Gall bladder
• Kidney
• Blood vessels - Aorta
• Pancreas
• Ribs cartilage
• Pelvic structures
CALCIFICATION
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Abnormal structures that
contain calcium
Calcium indicates pathology
● Pancreas
● Renal parenchymal tissue
● Blood vessels and vascular aneurysms
● Gallbladder fibroids (leiomyoma)
Calcium is pathology
● Biliary calculi
● Renal calculi
● Appendicolith
● Bladder calculi
SOFT TISSUE - ORGANS
• Position of:
• Liver
• Spleen
• Kidneys
• Bladder
• Psoas muscle
• Fat planes
BONES
• Osteoarthritis –
degenerative changes
• Paget's disease –
sclerotic/ increase in
density
• Metastases – missing
pedicle sign
• Fractures – pathological
ostoeporosis
BOWEL OBSTRUCTION
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Large bowel obstruction
Intraluminal gas
Diameter greater than 5cm
Internal or external
obstruction can cause dilation
• mechanical large bowel
obstruction – cut-off
appearance
PARALYTIC ILEUS
• The large bowel can
also dilate with paralytic
ileus. In this condition,
the bowel is adynamic
(not undergoing normal
peristalsis).
Chronic ileus in a woman
with advanced
ovarian carcinoma that has
developed into a paralytic
ileus with long air-fluid
levels.
Major causes of adynamic ileus:
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Intra-abdominal
-Postoperative or post -traumatic
-Post inflammatory: pancreatitis, enteritis, colitis
-Pain-related: renal colic, epidural disease
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Extra-abdominal
-Septicaemia
-Metabolic disease
-Medications like narcotics
-Prolonged bed rest
SMALL BOWEL OBSTRUCTION
• Recognise small bowel
obstruction:
• Central appearance
• Visualise the valvulae
conniventes across width
of bowel
• Greater than 3cm less
than 5cm
• Fewer or greater number
of loops
• No gas in large bowel
RIGLER SIGN/ DOUBLE WALL SIGN
• Air on both sides of bowel
as intraluminal gas and free
air outside
• (usually requires >1,000 mL
of free intraperitoneal gas +
intraperitoneal fluid)
• Pneumoperitoneum
FOOTBALL SIGN
• Football sign" = large
pneumoperitoneum outlining
entire abdominal cavity
APPLE CORE SIGN
VOLVULUS
• Sigmoid Volvulus – torsion
of bowel, twisting around
the mesentery
• Coffee bean sign
TOXIC MEGACOLON
• Dilation of the transverse colon
• In the supine position, the
transverse colon is
normally the most anterior
and therefore the most
distended loop of large
bowel
• Abnormal dilatation of the
transverse colon starts with
at least 6 cm of transverse
diameter but, when
pathologic, is usually is
larger than that
• Thumbprinting from
submucosal infiltration
ARTEFACTS
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Percutaneous endoscopic
gastrostomy
tube
● Nasogastric tube
● Accidental
● Swallowed objects: razor
blades,
batteries, paper clips
● Objects placed inside
rectum or
vagina: caps, bottles,
vibrator
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Internal objects
• ● Iatrogenic
• ● Biliary or vascular
stent
• ● intrauterine coil
devices
• ● Sterilisation clips
• ● Surgical clips
External objects
• ● Incidental
• ● Stoma ring
• ● Objects in clothing:
coins, keys, comb
• ● Objects on clothing:
buttons, clips,
ARTEFACTS
Endovascular repair of
abdominal aortic aneurysm
REFERENCES
studentbmj.com
•
http://lifeinthefastlane.com
•
http://mededconnect.com
•
http://www.e-radiography.net/
•
http://radiologymasterclass.co.uk